Device for eliminating the front and end trimmings from series of rolls and for sorting the rolls

ABSTRACT

The device for removing front and end trimmings in a series of aligned rolls comprises: at least one continuous flexible suction conveyor ( 13 ); a suction system ( 3 ) associated with the conveyor so as to generate a suction through openings ( 13 A) in the conveyor; a device for eliminating trimmings along a roll transfer path; a device receiving rolls from the conveyor. The receiver comprises at least two alternate paths for the rolls, which are arranged in sequence along the conveyor ( 13 ) and onto which the rolls may be alternately sorted.

DESCRIPTION

1. Technical Field

The present invention relates to a device for removing front and endtrimmings from series of aligned rolls obtained, for example, bytransversely cutting logs of wound web-like material.

Devices of this kind are commonly used in the paper converting industryin order to eliminate the trimmings before packaging of the rolls ofpaper material, such as rolls of toilet paper, paper towels and thelike.

2. State of the Art

In the production of rolls of wound web-like material, for example rollsof toilet paper, paper towels or other paper material, winding of theweb-like material into so-called logs, i.e. rolls with a diameter equalto that of the finished rolls and with a considerable axial length, isperformed. The latter are then cut perpendicularly to their axis bymeans of so-called saw machines. During cutting of the logs, a fronttrimming and an end trimming are generated and must be eliminated beforethe subsequent roll-packaging operation and possibly recycled.

In order to eliminate the trimmings, various devices of a mechanicaltype have been developed. More recently, devices which performelimination of the trimmings from the series of cut rolls with the aidof pneumatic means have been developed.

An example of a pneumatic device for eliminating trimmings is describedin U.S. Pat. No. 5,475,917. In one of the embodiments described in thispublication, the front and end trimmings of the series of rolls cut fromthe logs and subsequently fed to the device are eliminated byinterrupting in a suitable zone the suction exerted by a flexiblesuction conveyor which removes the rolls from a feeder and transfersthem to a receiver. By suitably positioning and dimensioning thenon-sucking zone and using a conveyor of suitable length, it is possibleto ensure that the front and end trimmings are always located in theposition where the suction through the conveyor is interrupted.

Another system for eliminating the trimmings based on the use ofpneumatic means in combination with mechanical means is described inU.S. Pat. No. 5,458,033. This system envisages a suction conveyordivided into three portions, a central portion and two side portions,which may be staggered with respect to each other.

In the production and packaging of rolls of wound strip-like materialthere also exists the need to sort the rolls onto separate conveyorsdepending on the specific requirements during the processing phase. U.S.Pat. No. 4,033,862 describes a sorting device which is able to receive,at its input, a series of rolls from which the trimmings have alreadybeen eliminated, in order to distribute them in accordance with apredetermined criterion on a series of conveyors arranged in succession.This device is not able to eliminate the trimmings.

OBJECTS AND SUMMARY OF THE INVENTION

The object of the present invention is to provide a device for removingthe front and end trimmings in a series of aligned rolls, for examplerolls of paper or other web-like material, obtained by cutting the logs,which also allows sorting of the rolls to be performed.

This and further objects and advantages, which will become clear topersons skilled in the art from reading the text which follows, areobtained with a device in which a conveyor associated with a system forretaining the rolls transfers the rolls, once the trimmings have beeneliminated from them, onto a receiver which comprises at least twoalternate paths arranged in sequence along the conveyor itself and inwhich the conveyor is equipped with a sorting system for releasing therolls alternately to either one of the paths of the receiver.

In a practical embodiment, the conveyor is a suction conveyor associatedwith a retaining system of the suction type for retaining the rolls. Asa result it is possible to obtain a compact device and a particularlysimple and low-cost configuration of the sorting means which allowtransfer of the rolls to either one of the alternate paths. Eliminationof the trimmings is also obtained in a simple manner.

The conveyor with the associated suction system may be positioned so asto be arranged above the rolls which are fed to it, so as to retain thelatter from above. However, this is not strictly necessary since thepneumatic grip exerted by the suction means may also be orientednon-vertically, provided that it is opposed by the force of gravity, dueto the effect of which the trimmings are discharged. For example, theconveyor may be located laterally with respect to the rolls.

In a practical embodiment, the suction system associated with theconveyor comprises at least one first and one second suction member. Thetwo suction members are arranged in series along the extension of theconveyor and the sorting system acts at least on the second suctionmember arranged downstream of the first suction member with respect tothe direction of advancing movement of the conveyor, so as to activateor deactivate alternately the second suction member. In this way, whenit is required to sort the rolls from the device for removing thetrimmings onto the first of the alternate paths (i.e. onto the pathwhich is first encountered by the rolls fed by the conveyor) the secondsuction member is deactivated. In this way, the rolls are necessarilyreleased by the conveyor to the first of the said alternate paths. Whenit is desired to release the rolls onto the second alternate pathencountered during the advancing movement of the conveyor, the secondsuction member is activated, such that the rolls are retained by theconveyor until they reach the point where they may be released to thesecond alternate path.

The idea explained above may be extended to a configuration with morethan two alternate paths and consequently with more than two suctionmembers arranged in succession along the roll conveyor. In any case, therolls will be released to that path of the receiver which is locatedimmediately downstream (with respect to the direction of advancingmovement of the rolls) of the last active suction member.

The various suction members may consist of successive portions of a wallalong which the conveyor travels. The wall portion furthestdownstream—corresponding to the suction member which must be deactivatedwhen the rolls must be released to the first alternate path—has,associated with it, an intercepting member for intercepting the suctionthrough this wall portion. When there are more than two alternate paths,the wall portions along which the conveyor travels and which may beequipped with intercepting members are at least equal to the totalnumber of alternate paths less one. Each intercepting member may beactuated independently of the others.

According to a particularly advantageous embodiment of the invention,the suction system comprises a suction box with a wall or walls alongwhich the conveyor travels. Suction openings are formed along the wallor walls and are divided into a number of groups corresponding to thenumber of alternate paths along which the rolls fed by the conveyor maybe discharged. The various wall portions, with the exception, whereapplicable, of the first one, are equipped with suitable interceptingmembers. In practice, the suction box may be single and interception ofthe openings of the second group of openings is obtained by simplyactuating an intercepting system, for example a laminar valve. However,according to a preferred embodiment, the suction box is divided into anumber of chambers corresponding to the number of alternate pathsprovided in the roll receiver. In this case the first chamber may beconstantly in communication with the respective series of openings ofthe first group. In the second chamber, and where applicable in eachsuccessive chamber, a respective intercepting member for interceptingthe suction through the respective openings is provided.

In general, interception may occur by means of a valve or a tap on asuction duct which connects the suction chamber to a suction device orequivalent. In practice, however, in order to accelerate the response ofthe system to actuation of the intercepting member, the latter isadvantageously formed by a laminar valve which slides over the openingsof the respective chamber or using some other equally rapid operatingsystem.

In this way immediate interception or opening of the suction in therespective group of openings is obtained.

In the detailed description which follows, a specific and particularlyadvantageous system for eliminating the trimmings, resulting in aversatile and compact device, is described. It must be understood,however, that the specific type of system for eliminating the trimmingsand its structural and functional characteristics are not critical forthe realization of the present invention. The trimmings may beeliminated also using means different from the specific means described,for example using a system of the type known from the state of the artor other equivalent system. Solely the presence of a suction system forgripping the rolls is of relevance for the purposes of the presentinvention.

Further advantageous features and embodiments of the device according tothe invention are indicated in the accompanying dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood with reference to thedescription and the accompanying drawing, which shows a practicalnon-limiting example of said invention. In the drawing:

FIG. 1 shows a side and partially sectioned view of the device in afirst operating condition;

FIGS. 2 and 3 show local cross sections along II—II and III—III in FIG.1;

FIGS. 4 to 6 show three successive operating phases of the device duringelimination of the trimmings; and

FIGS. 7 to 10 show three successive operating phases of a modified formof the device during elimination of the trimmings and a cross section ofthe modified device, similar to the cross section in FIG. 2.

DETAILED DESCRIPTION OF AN EMBODIMENT

The device comprises a pair of side walls 1, between which a suction box3 divided into two chambers 3A and 3B by a separation baffle 5 isarranged. The chamber 3A is connected to a suction duct 7A, while thechamber 3B is connected to a suction duct 7B. The separation baffle 5may be omitted and the suction duct may be single instead of double. 9denotes the end wall of the suction box 3, which wall is divided intotwo portions 9A and 9B corresponding to the chambers 3A and 3B intowhich the suction box is divided. Openings 11A are formed in the wall9A, while openings 11B are formed in the wall portion 9B.

One or more flexible conveyors 13 travel along the bottom surface of thewall 9. The number of flexible conveyors 13 (two in the exampleillustrated) corresponds to the number of roll feed channels. The twoconveyors 13 are arranged parallel to each other, as shown in the crosssection in FIG. 2, and are arranged so as to receive simultaneously tworows of rolls supplied from a two-channel saw machine (not shown).

The flexible conveyors 13 are driven around a first idle roller 15 and asecond motorized roller 17. The roller 17 receives the movement from amotor which, in the example illustrated, is indicated by 19 and arrangedcoaxially with the roller 17.

Each flexible conveyor 13 has openings 13A which extend along its wholeextension. The openings 13A are flanked by lips 13B which also extendalong the whole extension of the conveyor 13. In the bottom zone of thepath of the conveyors 13, where the latter make contact with the bottomsurface of the wall 9 of the suction box 3, a suction obtained by meansof the vacuum generated inside the chambers 3A and 3B is producedthrough the openings 13A. In a manner known per se, the suction exertedthrough the openings 13A has the function of retaining the rolls fed tothe conveyors 13 in the manner which will be described below.

Chain wheels 21 are also supported idle, by means of suitable bearings,on the shaft 23 on which the roller 15 is supported. Similar chainwheels are mounted on the shaft 24 supporting the roller 17. Assembly issuch that the motor 19 which causes rotation of the roller 17 does notact on the chain wheels mounted on said shaft 24, the latter wheelsbeing supported idle and thus being able to be actuated with an actuatordifferent from and independently of the motor 19. Another two pairs ofchain wheels, denoted by 27 and 28, are also mounted between the sidewalls 1.

Respective chains 31 are driven around the chain wheels and extend alonga closed path, the bottom section of which is approximately parallel tothe path of the conveyors 13 in the zone where the latter make contactwith the external surface of the bottom wall 9 of the suction box 3.

Two membrane obturators 33A and 33B which are impermeable to air extendbetween the two chains 31 which are parallel to each other. The twomembrane obturators 33A and 33B are located in two opposite positionsalong the path of the chains 31.

The movement of the chains 31, and therefore of the associated membraneobturators 33A and 33B, is obtained by means of a motor 35 associatedwith one of the shafts of the chain wheels, in the case illustrated withthe shaft on which the chain wheels 28 are keyed.

The movement of the chains 31 is indicated by the arrow f31, while thatof the conveyors 13 is indicated by the arrow f13.

A roll feeder 41 is located in the inlet zone of the device. The rolls Rare fed in series, each series having a front trimming RT and an endtrimming RC representing the portions of surplus material which must beeliminated by means of the device described. The feeder 41 is generallyshown as a continuous conveyor, but may assume any suitable form and maybe suitably equipped with thrusters which facilitate feeding of theseries of rolls. The arrangement is known per se and variousalternatives are available for the person skilled in the art.

The device also comprises a roll receiver consisting, in the exampleillustrated, of two alternative paths defined by a first flexibleconveyor member 45 and by a second flexible conveyor member 47. Theflexible conveyor members 45 and 47 are actuated by the same motor 19which operates the conveyors 13, by means of a belt drive 49, 50.

Each of the flexible conveyor members 45, 47 has, in the exampleillustrated, at least one section approximately parallel to the bottomwall 9 of the suction box 3 and therefore to the respective section ofthe conveyors 13 making contact with the external surface of said wall9. The arrangement of the flexible conveyor members 45, 47 with respectto the conveyors 13 is such that, along the feed path of the rolls Rtransported in the direction of the arrow fR by the conveyors 13, saidrolls encounter firstly the flexible conveyor member 45 and onlysubsequently the flexible conveyor member 47.

A laminar valve 53 equipped with openings 55 and capable of moving in analternating manner in the direction of the double arrow f53 so as tocause, respectively, the openings 55 to communicate with the openings11B or be staggered with respect to the latter is arranged inside thechamber 3B of the suction box 3. For this purpose, the openings 55 and11B have substantially the same amplitude and a similar shape. Thelaminar valve 53 therefore allows the openings 11B to communicate withthe chamber 3B or to intercept said openings 11B, interrupting thesuction through them, effected via the duct 7B.

Operation of the device described hitherto is as follows (see inparticular FIGS. 4 to 6).

The feeder 41 feeds series of rolls R underneath the bottom section ofthe conveyor 13. Since the feeder 41 extends right underneath thesuction box 3 and since it is positioned so that the fed rolls R arelocated with their upper part making contact with the lips 13B of therespective conveyor 13, the suction generated through the openings 13Aof the conveyors 13 retains the rolls which form a seal against saidlips 13B. Consequently, the rolls R are transferred in the direction ofthe arrow fR toward the receiver.

If the laminar valve 53 is located in a position such as to close theopenings 11B in the portion 9B of the wall 9 corresponding to thesuction chamber 3B, the suction and therefore the retaining effect onthe rolls R ceases opposite the first flexible conveyor member 45.Consequently, the rolls R are released to the flexible conveyor member45 and further conveyed in the direction of the arrow f45 towardfollowing processing stations. This is the situation illustrated inFIGS. 4 to 6.

If, on the other hand, the laminar valve 53 is in a position such as tokeep the openings 11B open and in communication with the suction chamber3A, the retaining effect due to suction on the rolls R is maintained asfar as the end zone of the suction box 3, opposite the flexible conveyormember 47. The rolls R are in this case released by the conveyor 13 tothe flexible conveyor member 47 which transfers them in the direction ofthe arrow f47 toward a further processing station. This is the situationillustrated in FIG. 1.

Elimination of the front and end trimmings is obtained as follows (FIGS.4 to 6): the position of the end trimming RC of a first series of rollsand the front trimming RT of the following series is known from the datasupplied by the saw machine arranged upstream of the device (and notshown). It is therefore possible, by means of the motor 35, to cause themovement of the chains 31 and the membrane obturators 33A and 33B sothat one of the two obturators 33A, 33B is arranged between the bottomsection of the conveyors 13 and the end trimming RC and front trimmingRT when the latter are positioned by the feeder 41 underneath thesuction box 3. In this embodiment, the distance between the trimmings RCand RT corresponds approximately to the length of the obturators 33A,33B. Consequently, the retaining suction effect is not exerted on thetrimmings RC and RT, which fall toward a collection zone in the spacebetween the terminal end of the feeder 41 and the start of the flexibleconveyor member 45. A container or a suitable conveyor (not shown)collect and/or convey away the trimmings.

The movement of the chains 31 and consequently the obturators 33A, 33Bcontinues—at the same speed as the conveyors 13—until the obturatorwhich has intercepted the suction opposite the trimmings just discardedis positioned beyond the suction box 3. From this position, the membraneobturators 33A, 33B will be displaced by means of movement of the chains31 so as to be positioned for subsequent operation in order to eliminatesuccessive front and end trimmings. The presence of two obturatorsallows one or other of the two obturators to be used alternately,resulting in more rapid positioning of said obturators in preparationfor operation thereof.

FIGS. 7 to 10 show, in three different and successive operatingconditions, a modified embodiment of the invention. Similar numbersindicate parts which are the same as or correspond to those in theprevious embodiment. The device as claimed in FIGS. 7 to 9 differs fromthe previous device in that two pairs of chains 31A, 31A and 31B, 31B,which are driven around respective chain wheels and which are visible inparticular in the cross section shown in FIG. 10 (equivalent to thecross section shown in FIG. 2), are provided. A first membrane obturator33X is attached to the chains 31A driven around the wheels 21A and thewheels 19A, 27A and 28A, while a second membrane obturator 33Y isattached to the chains 31B. The two pairs of chains 31A, 31A and 31B,31B are actuated by independent motors denoted by 35A and 35B in FIGS. 7to 9. In this way, the two pairs of chains and consequently the twomembrane obturators may be displaced along the path defined by saidchains in an independent manner by means of the two motors. As a result,it is possible to obtain certain advantages which will emerge clearlyfrom the description of operation, with reference to FIGS. 7 to 9.

FIG. 7 shows the instant in which the end trimmings RC reach the suctionconveyors 13. The two membrane obturators 33X and 33Y are locatedadjacent to each other, with the front edge of the membrane obturator33X in a position such as to come into contact with the end trimmingsRC. When the end trimmings RC are situated in front of the membraneobturator 33X, the latter begins to move in the direction of feeding ofthe rolls, at the same speed as the latter, being controlled therein bythe respective chains 31A and by the motor 35A. FIG. 8 shows the firstphase of movement of the obturator 33X which accompanied the endtrimmings RC to the falling zone.

Vice versa, the chains 31B and the membrane obturator 33Y may remain ata standstill. The advancing movement of the membrane obturator 33Y willstart in synchronism with the advancing movement of the front trimmingsRT of the following series of rolls. FIG. 9 shows the instant in whichthe obturator 33X has reached and surpassed the pair of wheels 19A,while the membrane obturator 33Y is advancing in front of the first rollof the following series, which has yet to reach the point of separationfrom the pneumatic retaining system. The membrane obturator 33X mayadvance to this point at high speed until it reassumes the positionshown in FIG. 7 in order to start a following roll discharge cycle,independently of the speed of advancing movement of the membraneobturator 33Y, owing to the use of two independent driving systems forthe two obturators.

The substantial advantage which is obtained with this configurationcompared to that described previously consists in the fact that thedistance between the end trimmings RC and the front trimmings RT may beany and is not dependent upon the longitudinal dimension of theobturators 33X, 33Y. In fact, these two obturators act independently ofeach other on the end trimmings and on the front trimmings,respectively. Any greater or lesser distance between the end and thefront of successive series of rolls is compensated for by simplydelaying more or less the start of the movement of the second obturator33Y with respect to the first obturator 33X. As can be seen from FIGS. 7to 9, in fact, the distance between the front and end trimmings isgreater than the sum of the longitudinal lengths of the two obturators.Nevertheless, having delayed the start of the advancing movement of thesecond obturator with respect to the first one, it has been possible todischarge both the front trimmings and the end trimmings.

Moreover, since the first obturator 33X, once it has reached theposition in which the rolls leave the pneumatic retaining system, isable to advance at a speed greater than and independent of the speed ofthe rolls, in this configuration it is not necessary to provide on thesame pairs of chains several obturators which act alternately insuccessive operating cycles, as instead envisaged in the precedingconfiguration. In fact, there is sufficient time for the obturator 33Xto position itself again at the working point while the obturator 33Y isstill advancing at the (slower) speed of the rolls. Moreover, the activeoperating phase of the obturator 33X is able to start even before thesecond obturator 33Y is correctly positioned in the operating positionfor eliminating the front trimmings of the following series of rolls.

The system thus configured has an even greater flexibility andadaptability to any operating condition, it being possible to programfrom a keyboard or other suitable interface all the movements of theobturators so as to allow adaptation to any size of the rolls and to anylength of the series of rolls as well as to any distance betweensuccessive series of rolls.

The example in FIGS. 7 to 9 shows a configuration in which the rolls aresorted onto the flexible conveyor 47, as an alternative to the previousconfiguration where the conveyor 45 was active. The system fordischarging the trimmings may also operate without the means for sortingonto two or more roll sorting and discharge paths, as may the sortingsystem also operate with a different system for discharging thetrimmings.

The device described, when it has both the sorting system and the systemfor eliminating the trimmings (in either one of the configurationsdescribed), allows simple and rapid sorting of the rolls R alternatelyonto the conveying member 45 or onto the conveying member 47, dependingon the requirement in each case in the production cycle. The transitionfrom one of the two flexible conveyor members to the other may berequested, for example, depending on the type of manufactured articlefed in each case to the device or depending on the operating conditionsof the machines downstream.

It is clear that the concept described here with reference to a systemwith two flexible conveyor members 45, 47 may be further developed byenvisaging three or more flexible conveyor members arranged in series inthe direction of feeding fR of the rolls.

The device described also allows easy and rapid adaptation to thevarious sizes of the series of rolls arriving from the feeder 41.

Contrary to the devices of the prior art, in fact, the zone in whichsuction through the conveyors 13 is interrupted in order to allowdischarging of the trimmings may be positioned as required, beingdefined by the membrane obturators 33A, 33B or 33X, 33Y. This allows, inaddition to a high degree of flexibility, also a considerable limitationof the overall dimensions, since the length of the conveyors 13 on theone hand and of the chains 31 on the other hand are not dependent uponthe dimensions of the rolls and upon the overall length of the series ofrolls fed to the device, contrary to that which occurs in the devices ofthe prior art.

The adaptation of the device to the diametral dimension of the rolls isobtained—in a manner known per se—by means of heightwise adjustment ofthe side walls 1 with respect to the flexible conveyor members 45, 47and the feeder 41.

It is understood that the drawing shows only a simplification providedby way of a practical demonstration of the invention, the form anddimensions of said invention being able to vary without therebydeparting from the scope of the idea underlying said invention.

1. A device for removing front and end trimmings in a series of alignedrolls, comprising: at least one continuous flexible conveyor; aretaining system associated with said conveyor for retaining the rollson said conveyor; a device for eliminating trimmings along a rolltransfer path; a device for receiving the rolls from said conveyor;wherein said device for receiving comprises at least two alternate pathsfor said rolls, arranged in sequence along said conveyor; and whereinsaid conveyor comprises a sorting system for releasing said rollsalternately to either one of said at least two paths.
 2. Device asclaimed in claim 1, wherein said device for receiving comprises a firstflexible conveyor member defining said first path and a second flexibleconveyor member defining said second path.
 3. Device as claimed in claim2, wherein said two flexible conveyor members have a movement with atleast one component parallel to the direction of advancing movement ofthe said conveyor.
 4. Device as claimed in claim 3, wherein said firstflexible conveyor member has a section approximately parallel to theconveyor and an inclined section which diverges with respect to saidconveyor.
 5. Device as claimed in claim 4, wherein said inclined sectionof the first flexible conveyor member extends as far as underneath thesecond flexible conveyor member.
 6. A device for removing front and endtrimmings in a series of aligned rolls, comprising: at least onecontinuous flexible conveyor; a retaining system associated with saidconveyor for retaining the rolls on said conveyor; a device foreliminating trimmings along a roll transfer path; a device for receivingthe rolls from said conveyor; wherein said device for receivingcomprises at least two alternate paths for said rolls, arranged insequence along said conveyor; wherein said conveyor comprises a sortingsystem for releasing said rolls alternately to either one of said atleast two paths; wherein said conveyor is a suction conveyor, andwherein said retaining system is a suction system associated with saidconveyor so as to generate a suction through openings in said conveyor.7. Device as claimed in claim 6, wherein said device for receivingcomprises a first flexible conveyor member defining said first path anda second flexible conveyor member defining said second path.
 8. Deviceas claimed in claim 7, wherein said two flexible conveyor members have amovement with at least one component parallel to the direction ofadvancing movement of the said conveyor.
 9. Device as claimed in claim8, wherein said first flexible conveyor member has a sectionapproximately parallel to the conveyor and an inclined section whichdiverges with respect to said conveyor.
 10. Device as claimed in claim9, wherein said inclined section of the first flexible conveyor memberextends as far as underneath the second flexible conveyor member. 11.Device as claimed in claim 6, wherein said suction system comprises afirst suction member and at least one second suction member arrangeddownstream of the first suction member with respect to the direction ofadvancing movement of said conveyor, and wherein said sorting systemacts on said at least one second suction member so as to activate ordeactivate alternately said at least one second suction member. 12.Device as claimed in claim 11, wherein said first suction member andsaid at least one second suction member consist of respective portionsof a wall along which said conveyor travels and wherein at least thewall portion furthest downstream has, associated with it, a respectiveintercepting member for intercepting the suction through said wallportion.
 13. Device as claimed in claim 6 or 11 or 12, wherein saidsuction system comprises a suction box with a wall equipped with suctionopenings, along which said conveyor travels, and wherein said suctionopenings are divided into at least two groups arranged in succession inthe direction of advancing movement of said conveyor, an interceptingmember for intercepting said openings of said at least one second groupof openings being provided.
 14. Device as claimed in claim 13, whereinsaid suction box is divided into at least one first and one secondchamber arranged in series, the openings of said first groupcommunicating with the first chamber and the openings of said secondgroup communicating with the second chamber.
 15. Device as claimed inclaim 14, wherein a laminar valve is arranged slidably inside saidsecond chamber so as to close the suction openings of said second group.